Ponton-bridge



(No Model.)

s. N. STEWART.

PONTON BRIDGE.

No. 401.765. Patented Apr. 23, 1889'.

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UNITED STATES PATENT OFFICE.

SYLVESTER N. STEWART, OF PHILADELPHIA, PENNSYLVANIA.

PONTON-BRIDGE.

SPECIFICATION forming part of Letters Patent No. 401,765, dated April 23, 1889.

Application filed January 19, 1889. Serial No. 296,926 (No model.)

To all whom it may concern.-

Be it known that I, SYLVESTER N. STEWART, a citizen of the United States, residing at Philadelphia, county of Philadelphia, and State of Pennsylvania, have invented a new and useful Ponton Bridge, (not patented yet in any country,) of which the following is a specification.

My invention relates to that class of ponton-bridges in which an opening must be provided for the passage of boats and rafts. The object of my improvement is to furnish a draw that may be closed against a torrential current without strain and without the aid of other than manual power. I attain these objects by the construction shown in the accompanyin g drawing, which represents a plan View of the bridge, and in which A and A are two causeways of earth, piling, or boats. The two floating leaves B and B meet at b and form the draw. The leaves are hinged to each causeway at a a in such a manner as to swing freely, and are of such length relatively to the open water-way as, when closed, to have the form of a V. The leaves thus arranged can be drawn together with a hand-capstan that would be entirely inadequate to close a draw at right angles to the current; and such a draw will open and leave a water-way of a certain widthsay four hundred feetin one-half the time required by a one-leaf draw, for when each leaf shall have been moved two hundred feet by the force of the current an opening of M four hundred feet is obtained. The two leaves B B are drawn together by an ordinary cap- 3 5 stan and wire rope. When the rope is slackened, the pressure of the current forces the leaves apart, leaving an opening for boats to pass, the rope sinking to a considerable depth. Only the roadway c c c is shown, the form and arrangement of the boats beneath it being the subjects of other applications for patents,

as is also the method of bridging over the corners a a and h. For a foot-bridge, however, this bridge is complete as shown here without bridging the corners and without any boats beneath the leaves B B.

What I claim, and request to have protected by Letters Patent, is-

A bridge with a floating draw constructed of two floating leaves, one connected to each causeway in such manner as to swing freely, and of such length relatively to the open water-way as when closed to have the form of a V, substantially as and for the purpose described.

S. N. STEWART. Witnesses:

JAMES T. STANLEY, I. W. STANLEY. 

